Japanese Stealth Demonstrator To Fly This Year

The original ATD-X mock-up was used for radar cross-section trials that were undertaken in France. This year the flying prototype is slated to be unveiled (Photo: TRDI)

Speaking to the foreign affairs and defense committee of Japan’s upper house, defense minister Itsunori Onodera has confirmed that the Mitsubishi ATD-X (advanced technology demonstrator-experimental) future fighter demonstrator is on course to fly later this year, albeit with a slight delay. Originally to have been unveiled to the media in May, the ATD-X is now a few months behind schedule but should be revealed later this year, with a first flight to follow soon afterwards.

ATD-X is a project led by the defense ministry’s TRDI (Technical Research and Development Institute), with Mitsubishi as main contractor. The aim of the program is to build an experimental aircraft for evaluating the maturity and integration of advanced airframe and engine technologies for future fighters. The aircraft is also colloquially known as the “Shinshin” (spirit of the heart).

In late 2005 an ATD-X mock-up was used for radar cross-section tests at a range in France, and in the following year a one-fifth-scale radio-controlled model was built to test high-angle-of-attack controllability. Preliminary results from these trials led to a decision to proceed with a flying ATD-X demonstrator program in 2007, and a year later the mock-up was shown publicly for the first time at the Japan aero show.

It has been speculated that the project was initiated to apply pressure on the U.S. to sell the F-22 Raptor to Japan, although if true it was unsuccessful in that aim. However, it has subsequently evolved into a program that could lead to an indigenous sixth-generation fighter incorporating what is described as “I3” (informed, intelligent, instantaneous) technology. Among the technologies being explored are fly-by-light optic cable flight control, three-dimensional thrust vectoring and a “self-repair” flight control system that automatically recalibrates itself after failure or damage to the control surfaces.

Ishikawajima-Harima Heavy Industries (IHI) has developed the XF5-1 afterburning turbofan to power the ATD-X. The company has considerable engine expertise through a long history of licensed production of U.S. engines, and indigenous development of the F3 turbofan that powers the Kawasaki T-4 trainer. The XF5-1 has already undergone extensive testing.

The Japanese MOD has outlined a plan for an “F-3” fighter to replace Mitsubishi F-2s in Japan Air Self-Defense Force service in the late 2020s, and expects to make a decision in Fiscal Year 2018 as to whether to continue with an indigenous design or to proceed along a joint development path, as it did with the F-2 (an enlarged derivative of the Lockheed Martin F-16 airframe with Japanese systems). Flight-tests with ATD-X will validate whether Japanese technologies are mature enough to support a cost-efficient indigenous development program.